import * as Effect from "effect/Effect";
import * as Binding from "../../Binding.ts";
import * as Output from "../../Output.ts";
import type { Role } from "../IAM/Role.ts";
import { isBindingHost } from "../Lambda/Function.ts";
import type { FHIRDatastore } from "./FHIRDatastore.ts";

/**
 * Shared scaffolding for AWS HealthLake HTTP bindings.
 *
 * NOT exported from `index.ts` — every `{Op}Http.ts` in this service is a
 * thin `Layer.effect(Cap, make…HttpBinding({ … }))` over one of the builders
 * below. Everything except the operation and the IAM action list is
 * boilerplate: every HealthLake job operation is scoped to one FHIR data
 * store, whose id is injected as `DatastoreId` and whose ARN receives the
 * grant. The `Start*Job` operations additionally inject the bound
 * data-access role and a scoped `iam:PassRole` grant.
 */

/**
 * Build the impl Effect for a data-store-scoped HealthLake operation
 * (describe/list import and export jobs): the runtime callable injects the
 * bound {@link FHIRDatastore}'s id as `DatastoreId` and the deploy-time half
 * grants `actions` on the data store ARN.
 */
export const makeHealthLakeDatastoreHttpBinding = <
  I extends { DatastoreId: string },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.HealthLake.DescribeFHIRImportJob`. */
  tag: string;
  /** The distilled operation; `DatastoreId` is injected from the data store. */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the data store ARN. */
  actions: readonly string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* (datastore: FHIRDatastore) {
      const DatastoreId = yield* datastore.datastoreId;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}(${datastore}))`({
            policyStatements: [
              {
                Effect: "Allow",
                Action: [...options.actions],
                Resource: [Output.interpolate`${datastore.datastoreArn}`],
              },
            ],
          });
        }
      }
      return Effect.fn(`${options.tag}(${datastore.LogicalId})`)(function* (
        request?: Omit<I, "DatastoreId">,
      ) {
        return yield* op({
          ...request,
          DatastoreId: yield* DatastoreId,
        } as I);
      });
    });
  });

/**
 * Build the impl Effect for a HealthLake `Start*Job` operation: the binding
 * is constructed with the {@link FHIRDatastore} **and the data-access role**
 * (the IAM role HealthLake assumes to read/write the S3 locations; its trust
 * policy must allow `healthlake.amazonaws.com`). The runtime callable injects
 * the data store id as `DatastoreId` and the role's ARN as
 * `DataAccessRoleArn`; the deploy-time half grants `actions` on the data
 * store ARN plus `iam:PassRole` on the role — without the PassRole grant,
 * `Start*Job` fails only at runtime with an AccessDeniedException.
 */
export const makeHealthLakeStartJobHttpBinding = <
  I extends { DatastoreId: string; DataAccessRoleArn: string },
  A,
  E,
  R,
>(options: {
  /** Fully-qualified binding tag, e.g. `AWS.HealthLake.StartFHIRExportJob`. */
  tag: string;
  /**
   * The distilled operation; `DatastoreId` and `DataAccessRoleArn` are
   * injected from the bound resources.
   */
  operation: Effect.Effect<(input: I) => Effect.Effect<A, E>, never, R>;
  /** IAM actions granted on the data store ARN. */
  actions: readonly string[];
}) =>
  Effect.gen(function* () {
    const op = yield* options.operation;

    return Effect.fn(function* (
      datastore: FHIRDatastore,
      dataAccessRole: Role,
    ) {
      const DatastoreId = yield* datastore.datastoreId;
      const RoleArn = yield* dataAccessRole.roleArn;
      if (!globalThis.__ALCHEMY_RUNTIME__) {
        const host = yield* Binding.Host;
        if (isBindingHost(host)) {
          yield* host.bind`Allow(${host}, ${options.tag}(${datastore}, ${dataAccessRole}))`(
            {
              policyStatements: [
                {
                  Effect: "Allow",
                  Action: [...options.actions],
                  Resource: [Output.interpolate`${datastore.datastoreArn}`],
                },
                // CRITICAL: without iam:PassRole on the data-access role,
                // Start*Job fails only at runtime with an AccessDenied.
                {
                  Effect: "Allow",
                  Action: ["iam:PassRole"],
                  Resource: [Output.interpolate`${dataAccessRole.roleArn}`],
                  Condition: {
                    StringEquals: {
                      "iam:PassedToService": "healthlake.amazonaws.com",
                    },
                  },
                },
              ],
            },
          );
        }
      }
      return Effect.fn(`${options.tag}(${datastore.LogicalId})`)(function* (
        request: Omit<I, "DatastoreId" | "DataAccessRoleArn"> & {
          DataAccessRoleArn?: string;
        },
      ) {
        return yield* op({
          ...request,
          DatastoreId: yield* DatastoreId,
          DataAccessRoleArn: request.DataAccessRoleArn ?? (yield* RoleArn),
        } as I);
      });
    });
  });